An adzer machine is used in the rail industry to resurface worn cross ties, which are the base components of railroad tracks. Over time, support plates that connect rails to the cross ties are forced into the cross ties by the weight of the trains traveling along the tracks. And depending on a differing hardness of individual cross-ties, the support plates are forced deeper into some cross ties than into other cross ties. In order to maintain a straightness of the rails and ensure that the rails are adequately supported along their lengths, the support plates are periodically reset using the adzer machine.
To reset the support plates, one of the rails is separated from the corresponding support plates and the support plates are removed from the cross ties. A head assembly of the adzer machine is then moved along the cross ties at the locations from whence the support plates were removed. The head assembly includes a series of cutters mounted to a rotating hub. As the head assembly is moved along the cross ties, the cutters create a smooth level surface at each cross tie, the smooth level surface of all cross ties being set at a common height. The support plates and rail are then reconnected to the newly resurfaced cross ties.
An exemplary adzer assembly is described in U.S. Patent Application No. 2011/0094624 of Lee, Jr. et al. that published on Apr. 28, 2011 (“the '624 publication”). Specifically, the '624 publication discloses an assembly having a frame, a base plate attached to a center of the frame, an adzer unit rotatably connected to the base plate, and two skids connected fore and aft to the frame via a linkage system. Double-acting hydraulic cylinders are connected between the frame and the linkage system and used to raise and lower the skids relative to the adzer unit as the skids are pushed forward along cross ties of a railroad track.
While the adzer assembly of the '624 publication may perform adequately in some applications, the assembly could be problematic during a hydraulic failure condition. In particular, during a failure condition associated with the double-acting hydraulic cylinders (e.g., when the cylinders suddenly lose pressure), it may be possible for the skids to drop downward into the cross ties or into a space between adjacent cross ties during a transport operation. This uncontrolled movement could result in gashing of the cross ties and/or damage to the skids or adzer unit.
The head assembly of the present disclosure is directed at solving one or more of the problems set forth above and/or other problems in the art.